JP3407921B2 - Vascular catheter shaft - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vasodilator catheter shaft used for a vasodilator catheter of a medical device.

[0002]

2. Description of the Related Art A catheter is a device used for discharging and injecting body fluids and drugs from a body cavity or tubular organ.
In recent years, functionalization of catheters has advanced, and for example, a vascular dilatation balloon catheter used for percutaneous angioplasty to dilate a narrowed portion of a blood vessel, a urinary balloon catheter with a temperature sensor capable of simultaneous urination and bladder temperature measurement. Etc. have been applied. In particular, a balloon catheter having a balloon (expansion body) at its distal end is applied to various body cavities such as blood vessels, and its importance is increasing in the medical field.

Among such balloon catheters, a blood vessel dilatation catheter is applied to, for example, percutaneous angioplasty (PTCA) for dilating a stenosis formed in a coronary artery. In this PTCA, for example, the femoral artery is secured by the Seldinger method, the guiding catheter is inserted while operating the guide wire to the vicinity of the stenosis which is the target lesion, and then the blood vessel is expanded into the lumen of the guiding catheter. The catheter for insertion, position the balloon at the tip of the catheter at the stenosis, and then inflate the balloon by inflating a fluid for expansion such as a contrast agent into the balloon through the lumen formed in the catheter for vasodilation,
It is intended to expand the narrowed portion.

[0004] Such a vasodilator catheter is required to have a followability (trackerability) that allows it to easily pass through the guiding catheter and smoothly advance to a target lesion along a meandering blood vessel. In addition, the shaft has sufficient strength and its applicable tissue
Various flexibility is required for the parts.

The vasodilator catheter expands the balloon by pressurizing the inside of the balloon through a lumen formed therein. The expansion is usually about 7 atmospheres, and depending on the operator, 14 atmospheres or more. In some cases, the shaft is required to withstand pressure due to sufficient mechanical strength. Further, since the operation is performed inside the blood vessel, the diameter of the shaft is naturally required to be smaller than the diameter of the blood vessel. The stenosis in the coronary artery has an inner diameter of 3 mm or less even at a thick portion, and the shaft outer diameter is usually required to be 1.5 mm or less. It is necessary to form a lumen in the shaft having a small outer diameter and to increase the inner diameter in order to reduce the flow resistance of the expansion fluid. For this reason, it is necessary to make the wall of the shaft portion thinner, but unless the resin is excellent in mechanical strength, the pressure resistance is inferior, so it is impossible to make the wall thinner.

As the physical properties desired for the catheter shaft, appropriate flexibility, mechanical strength, workability, sterilization resistance, cost, etc. are emphasized, but in recent years, low frictional properties, especially in the body cavity, are required. Is becoming more common. That is, when the catheter is inserted into the respiratory tract, trachea, gastrointestinal tract, urethra, blood vessels, and other tissues, insufficient lubricity of the surface of the shaft may damage the tissue or cause inflammation. In order to prevent mucous membrane damage and inflammation due to friction, it is necessary to modify the surface of the material to provide lubricity when wet. For this purpose, it is preferable to use a highly reactive material as the shaft.

As a shaft material for a conventional vasodilator catheter, polyethylene (hereinafter, referred to as PCT / JP88 / 00202 and US Pat.
Abbreviated as PE), polypropylene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, polyvinyl chloride, polyamide elastomer, polyester, thermoplastic resin such as polyurethane, fluororesin, silicone rubber, latex rubber, etc. are disclosed. Has been done.

However, only PE can be put to practical use because it is too hard or lacks in strength. Although it is considered that the degree of flexibility represented by the above-mentioned polyolefin resin is required for use in a vascular catheter shaft, generally, the strength tends to decrease as the flexibility increases. In reality, there is a certain degree of flexibility, and it is a high-density PE that can maintain a pressure resistance of 14 atm or more even if it is made thin.
Was only.

Plasticized PVC (soft PVC) has been widely used for reasons such as appropriate flexibility, heat resistance, easy processability and low cost. The main reason for this is that the physical properties, particularly the flexibility, can be significantly controlled by the addition amount of the plasticizer.
Further, soft PVC is also a material that can be easily surface-treated.
However, the elution of the plasticizer, which is harmful to the human body, cannot be avoided,
Also, since it contains a large amount of plasticizer (30 to 70%),
There are problems such as low mechanical strength. Therefore, a resin that does not use a plasticizer and can control flexibility significantly and has sufficient mechanical strength is desired for catheter applications.

On the other hand, since fluororesin and PE are also flexible, they may be used for catheter applications, but the flexibility cannot be freely controlled, and even if the softest brand is selected, sufficient softness cannot be obtained. There are many. Further, since there is no lubricity when wet, some kind of surface hydrophilization treatment is required. However, fluororesin and PE are chemically extremely stable materials and are difficult to be surface-modified by plasma-initiated polymerization or the like. In addition, fluororesin and PE
Has poor adhesion to other resins and lubricants, and therefore has problems such as poor assembly processability into a catheter and lack of sustained effect when a hydrophilic polymer is surface-coated.

Polyurethanes and vinyl chloride urethanes are also used for catheters because of their ease of surface treatment and flexibility control, but urethanes are expensive and their biodegradability is a problem. It is said that.

[0012] Further, when the publicly known art concerning the conventional catheter for vasodilation is examined, emphasis is placed on improving trackability and emphasis is placed on controlling the flexibility of the catheter shaft by the shape. For example, US Patent No. 4
No. 977690 uses a PE as a material and gradually softens the diameter at the base and the tip of the shaft to make the tip flexible. In US Pat. No. 4,775,371, the tip of PE is coated with PE of varying density. There are some parts that have been made flexible. However, in these conventional techniques, the mechanical strength of the catheter shaft is emphasized, and in order to obtain flexibility, P
The diameter of E is reduced and the rigidity of the shaft is adjusted.
In particular, no consideration is given to the surface treatment.

From the above-mentioned problems, a resin which is easy to be surface-treated and has flexibility and strength for imparting antithrombogenicity and lubricity is desired for catheter applications.

[0014]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has a property required for a vasodilator catheter shaft applied to various body cavities, that is, sufficient mechanical strength. Achieves that flexibility can be significantly controlled, that surface treatment for imparting antithrombogenicity and lubricity is easy, and that safety is high (no elution of plasticizers that are harmful to the human body) An object is to provide a catheter shaft for vasodilation.

[0015]

The above objects are achieved by the present invention described in (1) to (11) below.

(1) A catheter shaft for vasodilation, which comprises an α-olefin polymer alone or a polyolefin polymer alloy containing at least 10 wt% of α-olefin polymer, having an elastic modulus of 1600.
0 kgf / cm ² or less, its compressive strength is 63 kg / cm ²
A catheter shaft for vasodilation characterized by the above. (2) At least 10 wt% of an α-olefin polymer alone or an α-olefin polymer having 4 or more carbon atoms
A catheter shaft for vasodilation using the above-mentioned polyolefin-based polymer alloy, having an elastic modulus of 160
00kgf / cm ² or less, its compressive strength is 63kg / c
The catheter shaft for blood vessel dilation according to (1) above, wherein the catheter shaft has a diameter of m ² or more. (3) The α-olefin polymer has an elastic modulus of 50.
The vasodilating catheter shaft according to the above (1) or (2), which is an α-olefin polymer having a weight of 00 kgf / cm ² or less. (4) The α-olefin polymer is polybutene-
1,1,2-polybutadiene, polyisoprene, polyisobutylene, propylene-butene copolymer and poly-
The catheter shaft for vasodilation according to (3) above, which is at least one selected from the group consisting of 4-methyl-1-pentene. (5) The α-olefin polymer is polybutene-
The catheter shaft for vasodilation according to (4) above, which is at least one selected from the group consisting of 1 and 1,2-polybutadiene. (6) The alloyed polymer of the polyolefin-based polymer alloy is polyethylene, vinyl chloride, polypropylene, ethylene-propylene copolymer and propylene-
The catheter shaft for vasodilation according to the above (1) or (2), which is at least one selected from the group consisting of butene copolymers. (7) The catheter shaft for vasodilation according to (6) above, wherein the alloyed polymer of the polyolefin-based polymer alloy is at least one selected from the group consisting of polyethylene and polypropylene. (8) The α-olefin polymer is polybutene-1.
The catheter shaft for vasodilation according to the above (1) or (2), wherein the alloyed polymer is polypropylene. (9) The catheter shaft for vasodilation according to the above (1) or (2), wherein the catheter surface is coated with a biocompatible substance. (10) The catheter shaft for vasodilation according to the above (9), wherein the biocompatible substance is plasma-treated on the catheter surface and then coated with a maleic anhydride compound. (11) The catheter shaft for vasodilation according to (9), wherein the biocompatible substance is plasma-treated on the catheter surface and then coated with an acrylic acid-based compound.

The catheter shaft for vasodilation of the present invention comprises, as a constituent material of the shaft, an α-olefin polymer or an elastic modulus of 16000 kgf / cm containing the same.
^Use a polyolefin-based polymer alloy of ² or less. By having the elastic modulus not more than the above, the catheter shaft for vasodilation has improved flexibility compared to the conventional one. The content of the α-olefin polymer in the polyolefin-based polymer alloy can be adjusted in the range of 10 to 100 wt%, but the content is 20 for good surface treatment.
It is preferably at least wt%, and the α-olefin polymer used is not particularly limited, but it is preferable to select a polymer having a low elastic modulus and a polymer having a high elastic modulus.

In the present invention, the α-olefin-based polymer is a polymer obtained from α-olefin having a side chain having a carbon number of 1 or more at the terminal α-position of a double bond, and is a hydrocarbon containing no hetero atom. A polymer. Examples of the α-olefin include propylene, 1-butene, butadiene, 4-methyl-1-pentene, 1-pentene, 1-hexene and the like. The α-olefin-based polymer in the present invention is obtained by polymerizing the monomer, but it may be a copolymer thereof or a copolymer containing a monomer other than α-olefin. .

That is, the flexibility can be easily controlled by changing the composition ratio by using an α-olefin polymer which is flexible and has excellent mechanical strength, either alone or as a polymer alloy. At this time, the mechanical strength, which is a characteristic of the olefin polymer, can be secured. Further, polyolefins such as polyethylene are chemically very stable and surface modification is difficult, whereas this can be achieved by using an α-olefin polymer. The reason for this is
This is because the polymer has a tertiary carbon-hydrogen bond and the bond is easily cleaved by plasma irradiation or radiation irradiation to generate a radical.

In the catheter shaft of the present invention, a low elastic modulus α-olefin polymer or a polyolefin polymer alloy containing 10 wt% or more of the polymer is used as a constituent material of the shaft. 500 as tensile elastic modulus
By using 0 kgf / cm ² or less of the α-olefin polymer as one component of the polymer alloy, it is possible to widely control the flexibility of the polymer to be alloyed. In this case, the tensile modulus is ASTM
The initial elastic modulus (Young's modulus) in the tensile test described in D638 and the like.

In the present invention, when a relatively hard shaft is produced, an alloy of α-olefin polymer having a tensile elastic modulus of 5000 kgf / cm ² or less and at least 10 wt% or more and a polymer having a tensile elastic modulus of more than 5000 kgf / cm ² is alloyed. Is effective, and the tensile elastic modulus is 5000 kg when making a relatively soft shaft.
An α-olefin polymer having a f / cm ² or less of at least 10 wt% and a tensile elastic modulus of 5000 kgf /
Alloys with polymers smaller than cm ² are effective.

The elastic modulus in the present invention is 5000 kgf /
Specific examples of the α-olefin polymer having a cm ² or less include polybutene, 1,2-polybutadiene, polyisoprene, polyisobutylene, propylene / butene copolymer, poly-4-methyl-1-pentene copolymer, and the like. Among them, polybutene-1 or 1,2-polybutadiene is preferable because of compatibility, ease of flexibility control and availability.

The partner of the polymer alloy with the α-olefin polymer can be freely selected, but polyethylene, ethylene / vinyl acetate copolymer, α-olefin polymer, ethylene / propylene copolymer, propylene / butene can be selected. Copolymers and the like are preferable, and among them, a polymer blend of polypropylene and polybutene-1 is particularly preferable because of good compatibility, excellent mechanical strength, easy surface treatment, and good moldability. The composition ratio of the alloy is arbitrary depending on the application, and the content of the α-olefin polymer having a low elastic modulus can be adjusted within the range of 10 to 100 wt%, more preferably within the range of 20 wt% or more. In this case, the resin may be metered and blended, melt-kneaded by a biaxial kneading extruder or the like, and then pelletized to prepare pellets of a catheter shaft raw material for vasodilation.

The polymer alloy means polymer blend, graft polymerization, block copolymerization, random copolymerization, ionic crosslinking, IPN (interpenetrating polymer network; interpenetrating polymer network).
It is a concept including etc. Further, when forming a polymer alloy, an alloying agent or a compatibilizing agent may be used if necessary. Further, the filler and the like can be freely mixed.

The catheter shaft for vasodilation of the present invention can be molded by ordinary extrusion molding or injection molding. It is also possible to perform multi-layer extrusion or the like. It is also possible to perform multi-layer molding and use the α-olefin polymer of the present invention or a polymer alloy thereof in the surface layer. The catheter shaft for vasodilation of the present invention has a low molding temperature and is easy to mold. Further, the post-processability such as stretching is also good due to the properties of the material.

Since the catheter shaft for vasodilation of the present invention uses the α-olefin polymer used as a raw material or a polymer alloy having one component thereof, the flexibility of the catheter shaft of the product can be easily determined by the composition ratio of the raw material polymer. It is possible to control. Therefore,
The flexibility can be controlled without using a plasticizer or the like.

Since the catheter shaft for vasodilation of the present invention contains an α-olefin polymer as one constituent, it can be surface-modified by plasma treatment or the like. That is, the hydrogen of the α-position tertiary carbon is easily extracted by the plasma treatment to generate radicals. Therefore,
Surface modification such as plasma-initiated graft polymerization is easy to perform.

The elastic modulus referred to in the present invention is, for example, the initial elastic modulus or Young's modulus described in JIS or ASTM in an ordinary tensile test, and the raw material pellets or catheter shafts are cut into sheets by hot pressing. After being molded into a shape, it is measured according to the method described. In that case, the test temperature is room temperature, and the test speed is 1 mm / min.

The catheter shaft for vasodilation of the present invention has a sufficient mechanical strength such that the compressive strength is 63 kg / c.
It is characterized by being m ² or more. The compressive strength referred to here is a known film equation: σ ₂ = pr / h (σ ₂ is the tensile strength of the film, and is the compressive strength in the present invention, and p is the applied pressure and r Is the radius and h is the wall thickness.) [S. Timosh
nko "Strength of Material"
s ", Part II, 2nd definition, p.
165, D.I. van Nostrand Compan
y Inc. , New York, N .; Y. (194
1)]).

Radius and wall thickness are measured from the cross section of the catheter shaft using a stereomicroscope. The pressure resistance test is performed at room temperature and pressurized with nitrogen gas, etc., and the pressure at the time of bursting is determined. The compressive strength is calculated from these measured values using the above-mentioned membrane equation.

[0031]

EXAMPLES Specific examples of the present invention will be described below.

Comparative Example-1 Polypropylene (abbreviated as PP; α-olefin having a relatively high elastic modulus; manufactured by Mitsui Petrochemical Co., Ltd., trade name Hipol, grade F40)
1) A catheter shaft having an inner diameter of 0.9 mm, an outer diameter of 1.07 mm, and a wall thickness of 85 μm was extrusion-molded by itself.

(Example-1) The polypropylene used in Comparative Example-1 and the tensile elastic modulus of 4300 kgf / cm.
² of polybutene-1 (abbreviated as PB; manufactured by Mitsui Petrochemical Co., Ltd., trade name Buron, grade P4000)
After blending at a weight ratio of 0:20, alloy pellets were prepared by biaxial kneading extrusion. Using this pellet, inner diameter 0.9mm, outer diameter 1.07mm, wall thickness 85
A μm catheter shaft was extruded and molded.

Example-2 The same as Example-1, except that the PP: PB blend ratio was 40:60.

Example 3 The same as Example 1 except that the PP: PB blend ratio was 60:40.

(Example-4) The same as Example-1, except that the PP: PB blend ratio was 20:80.

Example-5 The same as Example-1, except that the PP: PB blend ratio was 0: 100.

Comparative Example-2 A polyethylene shaft (hereinafter abbreviated as PE) alone was molded into a catheter shaft of the same size as in the example. The PE used was Mitsui Petrochemical Industry Co., Ltd., trade name HiZex, grade 3000B.

(Comparative Example-3) A catheter shaft having the same size as that of the example was molded from PE having a lower elastic modulus than that of the PE of Comparative Example-2. The PE used was Mitsui Petrochemical Industrial Co., Ltd., trade name HiZex, grade 5305E.

(Comparative Example-4) Soft vinyl chloride (hereinafter referred to as P
(Abbreviated as VC)) was prepared with the following formulation.
Kanegafuchi Chemical Industry Co., Ltd. Straight PVC S1001,1
Dioctyl phthalate (DO) manufactured by Kao Corporation
P) 55 parts by weight and a stabilizer were compounded by a conventional method and pelletized by an extruder. Using this PVC pellet, a catheter shaft having an inner diameter of 0.9 mm, an outer diameter of 1.07 mm and a wall thickness of 85 μm was extrusion molded.

Example 6 PE and PB (Mitsui Petrochemical Industry, grade M3110) used in Comparative Example-2 were mixed with each other.
After blending at a weight ratio of 0:50, alloy pellets were prepared by biaxial kneading extrusion. Using this pellet, inner diameter 0.9mm, outer diameter 1.07mm, wall thickness 85
A μm catheter shaft was extruded and molded.

Example 7 The PE used in Comparative Example-2 and 1,2-polybutadiene (abbreviated as RB; manufactured by Japan Synthetic Rubber, trade name JSR RB, grade 810) were 5
After blending at a weight ratio of 0:50, alloy pellets were prepared by biaxial kneading extrusion. Using this pellet, inner diameter 0.9mm, outer diameter 1.07mm, wall thickness 85
A μm catheter shaft was extruded and molded.

(Example-8) The PB of Example-6 (M31
10) and RB of Example-7 were blended at a weight ratio of 50:50, and then twin-screw kneading and extrusion were performed to prepare alloy pellets. Using this pellet, inner diameter 0.9m
m, the outer diameter was 1.07 mm, and the wall thickness was 85 μm.

(Test Example-1) Examples-1 to 8 and Comparative Example-
A hot-pressed sheet was prepared from the pellets 1 to 4, and the tensile test and the plasma processability of the sheet were compared and examined. The tensile test was carried out at room temperature according to ASTM D638. The surface treatment by plasma-initiated graft polymerization was carried out according to the method described in JP-A-2-263845. Specifically, low temperature plasma (Ar: 0.1 torr)
After irradiation with r) for 10 seconds, MEA (methoxyethyl acrylate) was introduced into the gas phase under reduced pressure to perform graft polymerization. The treatability was determined by the feel of lubricity when wet.
The results are shown in Table 1 below.

[0045]

[Table 1]

(Test Example-2) Examples-1 to 8 and Comparative Example-
A pressure resistance test was performed on each of the catheter shafts 1 to 4. In the pressure resistance test, nitrogen gas pressure was applied to determine the burst pressure. The results are shown in Table 2.

Further, after plasma-initiated graft polymerization similar to that of Test Example 1 was performed, a maleic anhydride polymer was coated by a covalent bond by the method described in JP-B-1-33181 to improve the surface property which became lubricity when wet. The quality was done and evaluated.

[0048]

[Table 2]

As shown in Table 1, it is understood that the flexibility (elastic modulus) can be greatly changed in proportion to the composition ratio of the polymer alloy. Therefore, the flexibility of the catheter shaft for vasodilation of the present invention can be controlled by selecting the raw material polymer composition to be used.
As can be seen from Table 1, the PP / PB polymer alloy showed almost no change in breaking strength even when the composition ratio was changed.

The PP-only shaft of Comparative Example-1 was not preferable because it was too hard as a catheter shaft.
Regarding the flexibility of the relatively hard PE shaft of Comparative Example-2, the flexibility was improved in Examples-6 and 7. In addition, Example-8
The shaft was very soft like rubber. The flexibility of the shaft could be adjusted over a wide range depending on the type and type of α-olefin used.

The comparatively hard shaft of Comparative Example-2 is not so clinically preferable, and a more flexible shaft was desired. Therefore, a raw material polymer having an elastic modulus lower than that of Comparative Example-2 was selected. It can be said that the used vasodilator catheter shaft is preferable. Therefore, the elastic modulus is 16000k
It is preferably g / cm ² or less. P of Comparative Example-4
VC shaft has excellent flexibility, but withstand pressure is 10 kg / cm
^{It was} less than ² and weak in strength.

On the other hand, looking at the PEs of Comparative Examples-2 and 3, it can be seen that if the elastic modulus is lowered by some method, the strength is lowered. It is a well-known fact that the strength and elastic modulus decrease when a plasticizer or the like is blended or when the degree of polymerization or the structure of the polymer is changed. That is, when the elastic modulus is lowered to improve flexibility, the strength is generally lowered. It can be said that the property that the strength is maintained even if the composition ratio is changed like the PP / PB system is very preferable.
It shows that the flexibility can be freely controlled without considering the limitation of deterioration of physical properties.

In this example, it is obvious that the physical properties of the alloy can be significantly controlled if, for example, the PP used is an ethylene / propylene copolymer or the PB grade has a lower elastic modulus. Also,
A combination of PP and another polymer or PB and another polymer is also possible, and this embodiment shows only one part of the present invention and is not limited thereto.

Further, compared with PE, the PP / PB alloy was better in surface modification by plasma-initiated polymerization. It is considered that this is because PP / PB having tertiary carbon is more likely to draw hydrogen by plasma than PE having structurally secondary carbon. Therefore, in terms of easiness of imparting antithrombogenicity and lubricity to the material surface, the P
The P / PB-based polymer was superior.

The normal compressive strength decreases as the elastic modulus decreases, as seen in Comparative Examples 2 and 3 in Table 2.
Although mechanical strength required for a catheter shaft for vasodilation has a pressure resistance, conventionally, when it is made flexible, the pressure resistance is lowered. The necessary compressive strength must naturally withstand a normal balloon expansion pressure of 7 to 8 atmospheres, and it is necessary that the compressive strength withstand a pressure of at least 10 kg / cm ² or more. The pressure resistance can be increased depending on the thickness of the shaft wall, but this is not a preferable method. In order to make the expansion and contraction of the balloon smooth, it is necessary to increase the lumen formed in the shaft and reduce the flow path resistance. Therefore, the wall of the catheter shaft must be made as thin as possible.

With the size of the practical catheter shaft for vasodilation shown in Examples and Comparative Examples, the pressure resistance is 10 kg / c.
In order to achieve a pressure resistance of m ² or more, a pressure resistance of at least 62.9 kg / cm ^{2 is} required from the above-mentioned film equation. Preferably, the pressure resistance is 88 to withstand a pressure of 14 atmospheres.
Need more than kg / cm ² . 113 kg / cm ²
The above is more preferable. This is the size of the example, 1
It means to withstand a pressure of 8 kg / cm ² or more. Therefore, the vasodilator catheter shaft of the present invention can be applied to a high-pressure vasodilator catheter.

From Table 2, the pressure resistance of the catheter shaft of the PP / PB polymer alloys (Examples 1 to 5) is 24 kg / cm ² or more in all compositions, and even if the flexibility is improved, the rupture pressure and pressure resistance are lowered. Was not seen. This is also supported by the results of the tensile test of Test Example-1. That is,
This suggests that the flexibility can be freely selected without affecting the strength. This can be said to be a surprising advantage in view of the fact that the pressure resistance is lowered when the flexibility is conventionally improved. Further, the compressive strength of the catheter shafts of Examples 6, 7 and 8 is also 10 kg / cm ² or more, and the compressive strength required for the vasodilator catheter shaft is obtained.

From the above, the elastic modulus of the material used in the catheter shaft for vasodilation of the present invention is 16000 kg / c.
The reason why the compressive strength is set to m ² or less and the pressure resistance is set to 63 kg / cm ² or more is to provide a catheter shaft for vasodilation which is flexible and excellent in strength.

Regarding the surface treatment property, a surface treatment having lubricity when wet was possible with the entire composition of the PP / PB polymer alloy. Since the PE shafts of Comparative Examples 2 and 3 had poor plasma processability, the maleic anhydride-based polymer could not be covalently bonded to the surface and the coatability was poor. Therefore, although PE itself has a low friction property, a surface which becomes lubricated when wet is not obtained. on the other hand,
In Examples-6 and 7, surface treatment is possible. This is considered to be the property acquired by blending the α-olefin polymer. That is, this is an example showing that the vasodilator catheter shaft of the present invention facilitates the surface treatment that further enhances the low friction property originally possessed by the olefin polymer. Further, also in Example 8, the surface treatment could be easily performed.

Therefore, the catheter shaft for vasodilation according to the present invention can significantly reduce the frictional resistance on the surface. In particular, saliva, digestive fluid, body fluids such as blood and physiological saline, the wet resistance to water-based liquids such as water, that is, the friction resistance in a wet state is extremely small, therefore, the ease of insertion, pain relief of the patient, Advantages such as prevention of damage to the mucous membrane and intima of blood vessels can be easily obtained. Further, although the polyolefin polymer is a material having excellent biocompatibility, it has been conventionally unsatisfactory with respect to antithrombotic property, but it is possible to obtain antithrombotic property by coating with a hydrophilic polymer.

[0061]

EFFECTS OF THE INVENTION The catheter shaft for vasodilation of the present invention uses an olefin polymer as a material, which is mass-produced and contains at least 10 wt% of an inexpensive and highly safe α-olefin polymer. Its flexibility can be controlled without the use of agents. In addition, in relation to this, the vascular dilatation catheter shaft of the present invention has the advantage that it is a polymer alloy of a high molecular weight, so that there is no eluate due to the nature of the material and little drug adsorption. Also, due to the nature of the material, it has excellent chemical resistance. Further, due to the nature of the material, the catheter shaft for vasodilation of the present invention is excellent in heat resistance, creep characteristics and storage stability.

Further, since it has an appropriate melting point, it has good heat sealability. Therefore, the assembly work of the catheter is easy.

As shown in the examples, the catheter shaft for vasodilation according to the present invention can significantly control flexibility without impairing its strength. Further, it is possible to obtain a wide range of flexibility by combining the raw material polymers.

The catheter shaft for vasodilation of the present invention has a relatively low elastic modulus of 16000 kgf / in comparison with the conventional polyethylene catheter shaft for vasodilation.
The flexibility is improved by using the α-olefin polymer alloy having a cm ² or less, but the required pressure strength of 63 kg / cm ² is sufficiently retained. Therefore, it is possible to make the lumen formed in the catheter shaft for blood vessel expansion necessary for balloon expansion / contraction sufficiently large, and even if the thickness of the wall of the shaft is thinned, the lumen of 7 to 8 atm which is normally used can be used. Sufficiently withstands the pressure applied during balloon expansion. In particular, the polymer alloy of polypropylene and polybutene-1 has a high pressure resistance and can withstand a high pressure of 20 atm or more, so if it is possible to adapt to highly constricted bed cases such as titidid stenosis that requires high expansion pressure. It is a squeal. Further, since the catheter shaft for vasodilation of the present invention can adjust the rigidity of the shaft by changing the composition of the material polymer alloy,
It is possible to reduce the diameter of the entire shaft without impairing the operability of the catheter, particularly the pusher bilility. Therefore, not only the improvement of trackability,
Since it is possible to reduce the diameter, it is considered effective in securing blood flow to the coronary.

The catheter shaft for vasodilation of the present invention is inert and excellent in biocompatibility due to its material properties, but its surface treatment can dramatically improve antithrombogenicity and lubricity. This is because plasma-initiated graft polymerization is easier than that of polyethylene and the like. Ease of surface treatment means ease of catheter insertion, pain reduction for patients,
This means that it is easy to obtain advantages such as prevention of damage to the mucous membrane and intima of blood vessels.

─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-4-221572 (JP, A) JP-A-57-170266 (JP, A) JP-A-59-49777 (JP, A) JP-A-63- 192456 (JP, A) JP 60-34452 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) A61L 29/00-29/18 CA (STN) WPI (DIALOG)

Claims (8)

(57) [Claims] 1. A catheter shaft for vasodilation using an α-olefin polymer, having an elastic modulus of 16000 k.
gf / cm ² or less, pressure resistance Ri <br/> Ah at 63kg / cm ² or more, the α- olefin polymer, polybutene-1
Alone, a polymer block of polybutene-1 and polypropylene
Polymer blend of lend, polybutene-1 and polyethylene
A blend of lend, 1,2-polybutadiene and polyethylene.
Limer blend and 1,2-polybutadiene and polyb
Selected from the group consisting of polymer blends with Ten-1
At least one catheter shaft for vasodilation. 2. A catheter shaft for vasodilation containing at least 10 wt% of the α-olefin polymer , wherein the elastic modulus is 16000 kgf / cm ² or less and the pressure resistance thereof is 63 kg / cm ² or more. The catheter shaft for vasodilation according to claim 1. 3. At least the α-olefin polymer
Catheter shuff for vasodilation containing more than 20 wt%
And an elastic modulus of 16000 kgf / cm ² or less,
Has a pressure resistance of 63 kg / cm ² or more.
The catheter shaft for vasodilation according to claim 1. Wherein said α- olefin polymer is, vasodilation catheter shaft according to any one of claims 1 to 3 the elastic modulus is 5000 kgf / cm ² or less of α- olefin polymer. 5. The α-olefin polymer is polybutene.
The catheter shaft for vasodilation according to any one of claims 1 to 4, which is a polymer blend of Ten-1 and polypropylene . 6. The surface of the catheter is irradiated with plasma or emitted.
A contract characterized by surface modification by irradiation of rays
The catheter shaft for vasodilation according to any one of claims 1 to 5 . 7. After the catheter surface plasma treatment, a claim 1 in which coated with maleic acid compound
6. The catheter shaft for vasodilation according to any one of item 5 . 8. After the catheter surface plasma treatment, claims 1 those coated with acrylic acid compound
The catheter shaft for vasodilation according to any one of 5 above .